1. Field of the Invention
The present invention related to a brake system of automobile, and more particularly, to a brake control device for more effectively actuating the brake system of an automobile in braking a backward moving of the automobile.
2. Description of the Prior Art
In Japanese Patent Laid-open Publication 7-165041 it is proposed to control the distribution of the braking force between the front wheels and the rear wheels of an automobile, particularly a heavy track or the like in which a large mass of the vehicle body is centered at a relatively high position above the road surface, with the wheel base being relatively short, so that when the automobile is sharply braked in a forward running, the rear wheels lose much of the ground contact load, thereby correspondingly losing the tire grip for effecting the braking, while the rear wheels are substantially locked and slide over the road surface. According to the proposal, the supply of the brake fluid to the rear wheels is regulated by a regulator valve actuated in response to an imbalance of the suspension fluid pressures of the front and rear wheels which reflects thereon how the ground contact load of the wheels has shifted from the rear wheels to the front wheels, such that the supply of the brake fluid to the rear wheels is throttled by the regulator valve according to an increase in the imbalance of the suspension fluid pressures of the front and rear wheels. In this connection, it is also proposed not to actuate the regulator valve when the automobile is braked while climbing a relatively steep slope or when the automobile is braked when it is moving backward, so that normal full braking is available at the rear wheels.
In the above-mentioned prior art, the braking force available at the rear wheels is the normally available maximum braking force also available at the front wheels.